Question

(ii) 18, 15½, 13, ... is -47?​

Answer 1

Step-by-step explanation:

18,15

1/2

,13....−49

1/2

This sequence forms an A.P within first term a = 18

& the common different d = -2.5

The n

th

term of A.P is given by (a + (n - 1)d)

a+(n−1)d=−49

1/2

18+(n−1)(−2.5)=−49.5

18+(n−1)(−2.5)−49.5

(n−1)(−2.5)=−49.5−18

(n−1)(−2.5)=−67.5

(n−1)=

−2.5

−67.5

(n-1) = 27

n=28

Hence the number of terms in the sequence is 28 Answer